Thermostat



June 12, 1928. 1,673.255 H. R. LORANGER ET AL THERMOSTAT Original Filed June 2, 1924 ':'l E I Wm @M Mum attoznega Patented June 12, 1928.

UNITED STATES I 1,673,255 PATENT orrrcs,

HUBER! R. LORANGER, OF EILLSDALE, MICHIGAN, AND DALLAS D. PARSHALL, OF ALBANY, NEW YORK.

THERMOSTAT.

Original application filed June 2, 1924, Serial No. 717,345. Divided and this application filed July 12, 1926. Seria1No. 121,942.

This invention relates generally to thermostats designed for use in controlling the operation of motor driven refrigerating apparatus and more particularly to the specific construction and arrangement of the housing for such a thermostat.

This application is a division of our c0- pending application, Serial No. 717,345, filed June 2, 1924.

It is an object of this invention to obtain a construction which may be used with small installations, such as any ordinary household refrigerator, and which will maintain a substantially uniform temperature without oversensitiveness, which would cause too frequent starting and stopping of the motor.

In the type of thermostats now in use it has been the custom to provide a housing therefor constructed of a material of relatively low thermal conductivity, the walls of the housing usually being thinly constructed so as to be, incapable of storing an appreciable amount of heat. With such a housing the mere opening or closing of a refrigerator door would createa change in temperature sufficient to operate the thermostat. Such a condition is very unsatisfactory and is more than compensated for in the present invention by the novel construction of the housing which in addition to having walls of heat storing capacity is adapted to absorb the temperature from the brine tank as well as from the air for actuating the expansible chamber thus eliminating all unnecessary operations of the thermostat.

One type of construction often employed is to insert the expansible chamber in the compartment containing the brine, thus the expansible chamber will be effected only by the temperature of the brine. Moreover, this arrangement usually involves an expensive and none too satisfactory construction as in order to keep the well free from condensed atmospheric moisture it becomes necessary to fill the well with oil.

Another type of construction which is generally considered a more practical one is the use of a thermal coil formed by a double winding of tubing from the expansion chamber or tank around the expansible chamber for actuating the thermostatic switch. There are several disadvantages commonly experienced in prior constructions of this type which are eliminated by our invention.

cake of ice, therefore imparting no particular change in temperature to the bellows of the thermostat; second, the coil does not en'- close the bellows sufficiently to keep ofi the moisture adapted to collect and freeze there- 011, thus interfering with the expansion and contraction of the bellows which is necessary for eflicient operation of the switch.

In the present invention a combination of the temperature of the brine tank and a modified effect of the temperature of the air in the refrigerator is obtained. This modification is merely one'that postpones the effect of a short or temporary change in the air temperature permitting the latter to be lowered by contact with the brine tank, when the same is sufiiciently cold. This combination of the temperature ofthe air and of the brine tank through the housing has been found by long experimentation to give the ideal stability in the temperature of the refrigerator without unnecessary frequency of operation of the compressor.

With these and other objects in view, the invention resides in certain novel features of construction, combinations and arrangements of parts as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a vertical central section through the thermostat.

Figure 2 is a fragmentary perspective view of the construction shown in Figure 1.

Generally described our improved thermostat comprises a sealed expansible metallic chamber or bellows arranged within a housing and operatively connected with an electric switch or circuit closer mounted on the housing and controlling the'motor circuit. The cxpansiblc chamber is designated at A and is of the usual type containing a suitable fluid, the vapor tension causing the expansion and contraction of the chamber corresponding to temperature changes.

The member A is housed Within a casing B preferably formed of a material of relatively high thermal conductivity, such for instance is aluminum, and the walls of this housing are of suflicient thickness to provide for the desired heat storage capacity so that brine tank (not shown).

of thermostat havin of which are adapte this casing is adapted to function as a holdover. The capacity is such that fluctuations in the atmospheric temperature due to the opening or closing of the refrigerator door will not affect the thermostat, inasmuch as a lag is produced in the passage of heat through the housing walls.

The housing B is preferably in cu form, having its lower end closed by a cap 8, preferably having a threaded engagement therewith. An electric switch D of any suitable construction is mounted upon an insulated plate E, which is'in turn mounted on the top of the housing B. A plunger F is secured to the chamber A in any suitable manner and extends through a central aperture in the housing top and plate E, where it is connected to-the switch D.

With the construction as described the housing B is placed within the refrigerator,

preferably resting directly on the top of the In this position any change of temperature in the brine will be communicated directly b conduction in the housing B and by radiation from the.

latter into the 'enpansible chamber A. This will cause either the raising or the lowering of the plunger F and the subsequent operation of the electric switch D.

Thus, it will be readily apparent that we have provided a novel and improved type a housing, the walls to act as a holdover and which entirely eliminates a very undesirable feature now presentin' the ordinary type of thermostats used in refrigerating apparatus. Moreover there is provided a housing for the thermostat designed to absorb the temperature from the brine tank as well as from the circulating air in the refrigerator; consequently the temperature in the refrigerator is maintained substantially constant.

Another' very important advantage obtained by the present invention is the fact that the housing prevents the condensation and freezing of moisture on the bellows insuring an eflicient operation of the switch. To avoid danger of injury to the thermostat through corrosion of parts, the entire assembly is formed of non-corrodible materials. such as brass, Monel metal, aluminum, nickel, silver, etc.

While it is believed that from the fore going description, the nature and advantages of our invention will be readily apparent, we desire to have it understood that we do not limit ourselves to what is herein shown and described and that such changes ma be resorted to when desired as fall wit in the scope of what is cla med.

What weclaim as our invention is;

1. A tliermostat comprisin an expansible chamber and a housing within'which said expansible chamber is located, the walls of said housing having a relatively high coeflicient of heat transmission and being constructed and arranged to function as a holdover.

2. A thermostat comprising an expansible chamber and a housing within which said expansible chamber is located, the walls of said housing having a relatively high coeflicient of heat transmission and being constructed and arranged to function as a holdover, said walls being separated from said expansible chamber so as to exchange heat therewith substantially by radiation only.

3. A thermostat comprising an expansible chamber and a housin within which said expansible chamber is ocated, the walls of said housing being formed of a material of relatively high thermal conductivity and being of' sufiicient thickness to function as a holdovcr.

4. A thermostat comprising an expansible chamber and a housing within which said cxpansible chamber is located, the walls of said housing having a relatively high coefli cient of heat transmission and belng constructed and arranged to function as a holdover, whereby any sudden fluctuation in the atmospheric temperature will be prevented from effecting said expansible' chamber.

5. A thermostat comprising an expansible chamber and a housing for said expansible chamber having a relatively high coeflicient of heat transmission, ,said housing adapted to completely incase said expansible chamber, thereby preventing the condensation and the freezing of moisture thereon.

6. A thermostat comprising an expansible chamber and an inverted cup-shaped housing within which said expansible chamber is located, the walls of said housing being of sufficient thickness to function as a holdover.

7. A thermostat for a refrigerator having a brine tank comprising an expansible chamher and a housing within which said expansible chamber is located, the walls of said housing having a relatively high coefiicient of heat transmission and designed to funcabsorb the temperature from the brine tank ;-tion' as a holdover, said housing adapted to as well as from the air circulating within the refrigerator, whereby the temperature in the refrigerator is maintained substan-' tially constant and the operation of the expansible chamber is greatly reduced. v

In testimony. whereof we aflix our signa- 

